reputational headaches have been compounded by a glut of diamonds caused by a slump in consumer demand in China. That has dragged prices of top-quality cut diamonds down from about $12,000 per carat to $7,400 in five years, according to Rapaport-RapNet Diamond Trading Network, a price index.

Against this backdrop, a technological challenge is also emerging that could make it harder for the industry to win over the millennial customers on whom future sales depend. From China to California, boffins are improving their ability to cultivate diamonds in labs. They are looking beyond the billions of carats of synthetic diamonds produced under high temperature and pressure that are used in industries such as oil drilling. Now they are perfecting gem-quality stones for jewellery.

Only fitting that these narcissistic rocks that people have associated with wealth are finally coming into their own worthlessness. Jewelry means nothing against the backdrop of origin and acquisition.